261543674101525 has 12 divisors (see below), whose sum is σ = 324646104898692. Its totient is φ = 209020778627840.

The previous prime is 261543674101459. The next prime is 261543674101561. The reversal of 261543674101525 is 525101476345162.

It can be written as a sum of positive squares in 6 ways, for example, as 14741867756196 + 246801806345329 = 3839514^2 + 15709927^2 .

It is not a de Polignac number, because 261543674101525 - 2¹³ = 261543674093333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5353991422 + ... + 5354040271.

It is an arithmetic number, because the mean of its divisors is an integer number (27053842074891).

Almost surely, 2^{261543674101525} is an apocalyptic number.

261543674101525 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261543674101525 is a deficient number, since it is larger than the sum of its proper divisors (63102430797167).

261543674101525 is a wasteful number, since it uses less digits than its factorization.

261543674101525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10708032680 (or 10708032675 counting only the distinct ones).

The product of its (nonzero) digits is 6048000, while the sum is 52.

The spelling of 261543674101525 in words is "two hundred sixty-one trillion, five hundred forty-three billion, six hundred seventy-four million, one hundred one thousand, five hundred twenty-five".